1. Field of the Invention
The present invention pertains to a wireless communication system, a wireless access point, a communication control method, and a computer-readable medium having a communication control program including wireless access points using only wired communication lines and wireless access points employing wireless communication lines for connection to a backbone communication line.
2. Description of the Related Art
Recently, to centralize management of setting of wireless access points and management the access points during operation as well as the management of connection of wireless communication terminals or stations and sessions the stations for simplification of the management, there has been generally employed a wireless network including a system controller, e.g., an access point controller or a control server to manage the wireless access points and the wireless network.
In such wireless network simplified by use of the centralized management, the wireless access point includes a function for encapsulation in general. According to the encapsulation, the access point delivers user data from a station connected thereto to a destination of the data with a relay packet header (associated header information) added to the user data for the processing by, for example, the system controller.
In the wireless network, various control packets are communicated between the system controller and the wireless access points to manage the overall operation of the network. The control packets include information, for example, a setting parameter of a wireless access point and a change parameter during operation thereof, status information of the access point, connection information of a station, and a change processing instruction of an encryption key due to delivery of an encryption key or expiration of life time thereof.
In a conventional wireless communication system described in, for example, Japanese Patent Application Laid-Open Publication of PCT No. 2004-512787 (document 1), there is adopted an Internet Protocol Adaptive Layer (IPAL). By linking a data packet with an IPAL information packet, the header of a relatively small data packet is dispensed with to thereby lower the backhaul traffic.
Description will now be given of problems in the conventional techniques.
In a situation of the wireless network managed in a centralized way by use of the system controller, when a wireless communication line is employed as the backhaul communication line for connection from the wireless access point to the backbone network such as a wired Local Area Network (LAN) to resultantly configure a mesh network, there arise problems as below.
(Problem 1)
The associated header information added to the user traffic through the encapsulation consumes the band of the backhaul wireless communication line between wireless access points.
(Problem 2)
Various control packets used for the management consumes the band of the backhaul wireless communication line between wireless access points.
The technique of document 1 aims to reduce the amount of data in the packet header. However, consideration has not been given to the reduction in the control packet traffic and a scheme that makes it unnecessary to add the associated header information in the encapsulation.